Using Pixel layers as masks

[nschoenwald]

I have these templates (see attached files) that include pixel layers to use as masks for the "portrait" layer. What's the easiest way to apply these as masks so that the black parts of the layer are hidden?
This is day 1 for me for Affinity Photo and I can't figure this out after coming from Photopea before.

dynamic-token-templates-psd-2024-09-06.zip

Edited November 12, 2024 by nschoenwald

[GarryP]

Welcome to the forums @nschoenwald

My attached video shows one way to use a Pixel layer as a Mask – in the Layers Panel, drag the layer you want to use as a mask onto the thumbnail of the layer you want mask. (I toggle the layer visibility at the start just to show what's there.)

As you are using PSDs, which could contains a few ‘funny’ things, the process might be more difficult but it should be possible in some way.

[nschoenwald]

Unfortunately this does not seem to work with my template and I can't figure out why

[carl123]

All the pixel layers you want to use as masks are currently toggled off

Toggle their visibility on, after dragging them to their mask position

[nschoenwald]

Yeah I toggled them on. Appearantly they do get applied as masks, but they are inverted and when I do Layer -> Invert, nothing happens.

I made a screen recording here, maybe you can see what I'm doing wrong: https://www.youtube.com/watch?v=UBcYKWubnDQ

[GarryP]

I can see (mostly) what you are doing but since I don’t know what you are trying to do I can’t say what you are doing wrong, if anything.

Can you give us more details about what you are trying to do?

If you can share a visual example of what you are trying to achieve, and tell us what parts of that example you want to replicate, then that might help.

[Ldina]

1 hour ago, nschoenwald said:

Appearantly they do get applied as masks, but they are inverted and when I do Layer -> Invert, nothing happens.

I didn't look at your screen recording link, but I'll offer the following thoughts.

Masks, Adjustment Layers and Live Filter Layers are pure Alpha (ie, levels of transparency). So, an Alpha channel may be totally transparent (0% alpha), totally opaque (100% alpha) or partially transparent (like when using a gradient or a soft edged brush....values between 0% to 100% alpha). Those are "traditional" masks; for example, painting on a mask layer you have added with a soft black or white (or gray brush).

When you use a Pixel Layer as a Mask, it is usually fully opaque (unless you feathered the edges, lowered the opacity or added an effect to reduce the Alpha value). When you Invert the pixel mask, Affinity rasterizes the layer, which makes the Alpha = 100% (totally opaque). Even if the RGB pixel values change, the alpha (which is what the mask is all about) stays at 100%, so there is no change. 

If you right-click on your pixel mask (before or after moving it into the masking position over your thumbnail), you can select Rasterize to Mask. This will convert that pixel layer into a True "Alpha-only mask", which is pure alpha (levels of transparency, depending in the Alpha value). If that pixel layer had a gradient or other effect, it will translate over to your traditional mask as varying levels or alpha. Then, Inverting the mask will work like it does with other traditional masks. It's the Alpha channel that is the key.

This confused the Hell out of me for a while because it is different from the way it works in Photoshop (which I used for decades). I think I have this right, but someone will correct me if not. Hope that helps.